Benign prostatic hyperplasia (BPH) is the most common affliction of men over the age of 50. Despite numerous innovations in therapy for BPH including medical and minimally invasive surgical therapies (MIST), transurethral resection of the prostate (TURP) remains the most effective. In part, the shortcomings of MIST have been the lack of uniform baseline study entry criteria, poor elucidation of baseline criteria aid in therapeutic success and paucity of long-term data. Furthermore, there have been no studies that have attempted to stratify response to therapy based on ethnic variability. Recent data suggests that there may be varying distribution of symptoms, objective diagnoses, and functional / morphologic aspects of the prostate among different ethnic groups. Do minimally invasive alternative surgical therapies result in alternating levels of success among different ethnic groups? The Prostate Center at the New York Presbyterian Medical Center evaluates and treats an ethnically diverse group of more than 1,000 men per year with lower urinary tract symptoms secondary to BPH. In addition it has access to and currently employs all FDA approved MIST procedures, including transurethral microwave thermotherapy, TUNA, interstitial laser, water induced thermotherapy, holmium laser prostatectomy and electrovaporization. We propose to examine the role of MISTs designed to treat BPH a multi - ethnic group. The goals of this clinical trial are to determine the urodynamic changes in bladder function and outlet obstruction in patients with BPH treated by MIST. Parameters to be analyzed include peak detrusor pressure during voiding, detrusor pressure during maximal flow, Shafer resistance curves, Abrams - Griffiths contractility index and detrusor contraction duration. These parameters will be assessed to determine prognostic significance and correlated with long term improvement as determined by changes in the American Urologic Association Symptom Score (AUASx), uroflow and post void residual urine. Specifically, this study aims to evaluate in a highly diverse multi - ethnic population: 1. Urodynamic contractility and resistance parameters which change significantly after MIST 2. Baseline urodynamic parameters which may predict improved outcome after MIST 3. The success of various types of MIST in treating BPH in African - American, Hispanic and Caucasian men.